I've got to admit, I didn't properly understand what digital jitter is and how it affects sound. There's been quite a bit of discussion about it, so here is a collection of articles that explain it: Steve Nugent of Empirical Audio explains in easily understandable terms what jitter is and where it matters. The easiest article to read. You'll need to know the basics of digital transmission though, such as what S/PDIF, AES/EBU and optical digital are, for example. HDD Audio asks, Can you Hear Jitter? They also created files for a second test. However, I wonder, if you have a lo-fi system with lots of jitter, would you really hear a difference? Maybe more usefully, for those of you who think digital is just 0's and 1's, have a look at the picture below, from high-end digital gear, showing how digital waveforms, after they pass through equipment, aren't exactly "on" or "off any longer, but have measurable jitter: http://www.head-fi.org/forums/member...visualised.png Edit: There's also some discussion from Dan Lavry here which is interesting, as it discusses the actual harmonic effects of jitter. The subsequent posts in that thread from him are also interesting.